Question

which molecule is the building block of a nucleic acid?
disaccharide nucleotide monosaccharide
fatty acid amino acid peptide

Explanation:

Nucleic acids (like DNA and RNA) are polymers. Their monomers (building blocks) are nucleotides. A nucleotide has a nitrogen - containing base, a pentose sugar, and a phosphate group. Disaccharides and monosaccharides are related to carbohydrates. Fatty acids are part of lipids. Amino acids are the building blocks of proteins, and peptides are short chains of amino acids.

Answer:

nucleotide